title: The influence of carbamazepine on thyroid hormones and thyroxine binding globulin in hypothyroid patients substituted with thyroxine.
abstract: Carbamazepine (CBZ) decreases the serum concentration of thyroid hormones. It is proposed that CBZ increases the extra-thyroidal metabolism of thyroid hormones. In order to test this hypothesis CBZ was given to nine hypothyroid patients substituted with thyroxine (T4). A significant decrease in serum concentrations of T4, calculated free T4 (FT4), triiodothyronine (T3), and calculated free T3(FT3) was found after 3 weeks of CBZ medication. The serum concentrations of TSH and the T4:T3 ratios were unaltered, while the serum concentrations of T4-binding globulin (TBG) increased markedly in eight of the nine patients. These findings support the hypothesis of a CBZ induced increase in the extra-thyroidal metabolism of thyroid hormones.
mesh_terms: D000328:Adult; D002220:Carbamazepine / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood* / Q000627:therapeutic use; D013975:Thyroxine-Binding Proteins / Q000378:metabolism*; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D013975:Thyroxine-Binding Proteins; D014284:Triiodothyronine; D002220:Carbamazepine; D013972:Thyrotropin; D013974:Thyroxine